1. Field of the Invention.
The present invention relates to camera stands for supporting video and film cameras in operation.
2. Description of Related Art.
A variety of camera stands have been developed to secure the camera against unwanted movement while the camera is being operated. Camera stands typically have three legs which form a tripod to provide a stable base on a variety of different surfaces. The camera is mounted on the camera stand by a mechanism often referred to as the "head" which usually allows the camera to be panned or tilted. Because the camera stand is not always operated on a level surface, a leveling mechanism is often provided to level the camera head in relation to the tripod base. Once the camera head has been leveled, the head can be adjusted as needed to point the camera in the desired position to record an image.
An example of such a head and leveling mechanism is described in U.S. Pat. No. 4,579,436 to Jaumann. The Jaumann device includes a "ball and socket" type joint mounted above the tripod base, which allows limited movement of the head relative to the base. Once the head is leveled in the desired position, the head is locked in place.
One disadvantage of these prior camera stands is that the procedure for attaching the camera to the head and locking the head in the desired position is often a complex and time consuming procedure. These delays can be critical in news gathering and nature filming applications where important "shots" can be lost forever while the camera operator is setting up the camera on the camera stand or trying to adjust the head.
Besides being time consuming to operate, the mechanisms of many prior camera stand heads are often complex and expensive to manufacture. Moreover, dirt and other contaminants can jam and otherwise impede the proper operation of the head mechanisms.
Still further, these prior camera stand heads tend to be relatively tall and elongated. Consequently, the center of gravity of the camera is often substantially above the center of rotation of the head tilt mechanism, resulting in a degree of instability. This instability is particularly a problem for heavy cameras and telephoto lenses.
Various devices have been proposed to overcome some of these drawbacks. For example, U.S. Pat. No. 4,496,986 to Coutant, et al. describes a tripod with a "ball and socket" type joint which has three small plastic studs secured on the head of the tripod replacing the typical hemispherical socket. Such an arrangement is said to be less susceptible to contamination from dust and other particles. However, it is believed that the Coutant head has a relatively high center of gravity relative to the tilt center of rotation and has a complicated mechanism for locking the head in the desired position.
In U.S. Pat. No. 4,016,583 to Yeates, a ball and socket type camera stand head mechanism is described in which the ball is not locked by a locking mechanism to the underlying socket. Instead, it is proposed that the camera operator hold the camera supporting ball in place with one hand while operating the camera with the other hand. This device also appears to have a relatively high center of gravity. Moreover, it does not appear to be particularly well adapted for use with relatively large and heavy cameras.
U.S. Pat. No. 2,796,226 to Dalton et al. shows a "cradle" type head in which it appears that the center of gravity of the camera and head is close to the center of rotation of the head. However, this head mechanism appears to be relatively heavy and complex.